The present invention relates to a transit connection in a storage and forward switching system and, more particularly, to a multiple channel or transit trunk call control apparatus for transferring a transit message (packet) by call-disconnecting a switching network between switching offices.
In transfer between conventional storage and forward switching apparatuses of this type, calling is immediately performed when a transit message is stored even if switching offices are connected by leased lines or by a call disconnection type connection. In addition, calling can be controlled in only one channel with respect to one node between switching offices.
In the above conventional inter-switching-office system, when offices are connected through leased lines, a transit line cannot be used if the line is a switching network. Even in the call disconnection type connection which can use a switching network, if a switching network of a measured rate charging or cost system is used as a transit line, often only one message is can be transferred by one call connection rather than a plurality of messages. Therefore, an initial flat rate charging or cost range for the switching network cannot be effectively used.
In addition, in order to control a plurality of channels, independent call connection is performed for each channel. Therefore, multiple channel control taking into consideration a charging or cost system of a network cannot be performed (e.g., calling of the second channel is stopped when calling of the first channel is more inexpensive, or a subsequent channel is called to shorten storage time in accordance with a call amount).